Mechanically operated reciprocating conveyors



y 1966 K. M. ALLEN ETAL 3,253,700

MECHANICALLY OPERATED RECIPROCATING CDNVEYORS Filed Aug. 21, 1963 4Sheets-Sheet l INVENTORS KENNETH M. ALLEN CHESTER H- HARPER BUCKHORN,BLORE KARQUIST & SPARKMAN ATTORNEYS y 1966 K. M. ALLEN ETAL. 3,253,700

MECHANICALLY OPERATED RECIPROCATING CONVEYORS Filed Aug. 21, 1963 4Sheets-Sheet 2 FEED I 5 RETRACT DISTANCE FIG. 6

INVENTORS KENNETH M.AL EN CHESTER H. HARPER BUCKHORN, BLORE, KLARQUIST &SPARKMAN ATTORNEYS May 31, 1966 K. M. ALLEN ETAL 3,

MECHANICALLY OPERATED RECIPROCATING CONVEYORS Filed Aug. 21, 1963 4Sheets-Sheet 5 FIG. IO

FEED RETRACT DISTANCE INVENTORS KENNETH M. ALLEN CHESTER H. HARPERBUCKHORN, BLORE, KLARQUIST EL SPARKMAN ATTORNEYS y 1966 K. M. ALLEN ETAL3,253,700

MECHANIGALLY OPERATED RECIPROGATING CONVEYORS Filed Aug. 21, 1963 4Sheets-Sheet 4 FIG. 14

KENNETH M. ALLEN CHESTER H. HARPER INVENTORS. BY

BUCKHORN, BLOHE, KLAROUIST 8 SPARKMAN ATTORNEYS United States Patent3,253,700 MECHANICALLY OPERATED RECIIRGCATING CONVEYORS Kenneth M. Allenand Chester H. Harper, both of R0. Box 352, Newberg, Greg. Filed Aug.21, 1963, Ser. No. 303,599 4 Claims. (Cl. 198220) This invention relatesto reciprocating conveyors, and more particularly to reciprocatingconveyors which provide slow starting, accelerating feed strokes endingwith abrupt stops to toss materials being advanced by the conveyors.

In reciprocating conveyors which operate at comparatively lowfrequencies, as contrasted with vibratory conveyors which operate athigh frequencies, the ideal condition during the feed stroke is to startthe conveyor slowly so that static frictional engagement is maintainedwith the material being advanced, and thereafter constantly acceleratethe feeding movement of the conveyor below the point at which the staticfrictional engagement is broken between the conveyor and the materialand at the end of the feed stroke abruptly stop the feed stroke so thatthe material is thrown or tossed. There have been many attempts toachieve the tossing action in the prior art reciprocating or shakerconveyors, and the prior art structures attempting to achieve thisresult have been very complex, difficult to maintain and with imperfectachievement of this result.

An object of the invention is to provide a reciprocating conveyor inwhich a conveyor bed is advanced in a feed stroke gradually acceleratingto a high speed at the end thereof together with a sudden termination ofthe feed stroke so that material is thrown forwardly by the conveyorbed.

Another object of the invention is to provide a reciprocating conveyorwhich advances material with a tossing action and which is simple,effective and durable.

A further object of the invention is to provide a reciprocating conveyorin which a conveyor bed is advanced in the feed stroke thereof veryrapidly, and is brought to a stop quickly so that static frictionalengagement between the conveyor bed and the material being advanced isbroken.

Another object of the invention is to provide a reciprocating conveyorin which a conveyor bed is resiliently urged in one direction and isrestrained by a strand which passes under a crank member which isrevolved to intermittently pull the conveyor against the action of thespring.

Another object of the invention is to provide a reciprocating conveyorin which a connecting rod driven by a crank is connected at its otherend to a pivotal arm and to a link connected to a reciprocating conveyorbed.

Yet another object of the invention is to provide a conveyor in which aconveyor trough is suspended by pivotal links and is driven with aback-and-forth motion to advance material therealong.

The invention provides a reciprocating conveyor which includes areciprocable conveyor bed driven by flexible means connected thereto andto crank means together with means for guiding the flexible means toimpart to the conveyor bed a feed stroke in which the conveyor bedstarts slowly, accelerates to a high velocity and stops abruptly tothrow material being advanced thereby. In a reciprocating conveyorforming one embodiment of the invention there is provided a reciprocableconveyor bed urged in one direction by a spring and connected to one endof a strand which passes over a guide and is fixed at its other end andis engaged by a revolved crank members. Revolution of the crank memberpulls and re- 3,253,700 Patented May 31, 1966 ice leases the strand tocause, with the action of the spring, reciprocation of the conveyor.

In a reciprocating conveyor forming an alternate embodiment of theinvention, a conveyor bed is driven by a connecting link driven by acrank link, the links being connected to the free end of an arm pivotalon a fixed axis. The conveyor bed can be a straight trough or a spiraland can be suspended by links to enhance feeding action thereof.

A complete understanding of the invention may be obtained from thefollowing detailed description of reciprocating conveyors formingspecific embodiments thereof, when read in conjunction with the appendeddrawings, in which:

FIG. 1 is a fragmentary, partially sectional, side elevation view of areciprocating conveyor forming one embodiment of the invention;

FIG. 2 is a fragmentary, horizontal sectional view taken substantiallyalong line 2-2 of FIG. 1;

FIG. 3 is an enlarged, fragmentary, vertical sectional view taken alongline 3-3 of FIG. 2 showing parts of the drive of the reciprocatingconveyor of FIG. 1 in one position;

FIG. 4 is a view similar to FIG. 3 with parts thereof shown in differentpositions;

FIG. 5 is a diagram of the movement of the reciprocating conveyor ofFIG. 1;

FIG. 6 is a schematic view of a reciprocating conveyor forming analternate embodiment of the invention;

FIG. 7 is a side elevation view of a reciprocating conveyor forming analternate embodiment of the invention;

FIG. 8 is an enlarged, fragmentary, top plan view of the drive of theconveyor of FIG. 7, taken substantially along line 88 of FIG. 7;

FIG. 9 is an enlarged, fragmentary, side elevation view of the drive ofthe conveyor of FIG. 7;

FIG. 10 is a diagram of the movement of the reciprocating conveyor ofFIG. 7;

FIG. 11 is an elevation view of a reciprocating conveyor forming analternate embodiment of the invention;

FIG. 12 is a fragmentary, horizontal sectional view taken along line1212 of FIG. 11;

FIG. 13 is a fragmentary, horizontal sectional view taken along line1313 of FIG. 11; and

FIG. 14 is an enlarged, fragmentary vertical sectional view takensubstantially along line 14-14 of FIG. 11.

Referring now in detail to the drawings, there is shown in FIGS. 1 to 5a reciprocating conveyor including a reciprocating conveyor bed ortrough 10 mounted by rollers 12 for horizontal reciprocation. Theconveyor bed is reciprocated by a drive 16 which includes an electricmotor 18 driving a belt 20 to drive a fiy wheel 22. The fly wheel 22 iskeyed to a shaft 24 mounted in bearing 25 carried by vertical supportplates 26 and rotates crank arm 28 also keyed to the shaft 24 clockwiseas viewed in FIG. 1. The plates 26 are spaced apart by spacers 34 andare supported by a base 36. The crank arm 28 revolves sprocket 30 aboutthe center of the shaft 24. The drive reciprocates the conveyor bed tofeed matreial 32 with a throwing or tossing action toward the right, asviewed in FIG. 1. This is effected by starting the feed stroke slowly,accelerating to a high velocity and stopping the conveyor bed 10 sharplyat the end of the feeding stroke of the conveyor bed to break staticfrictional engagement between the material and the conveyor bed. Thedrive 16 then retracts the conveyor bed through a retraction strokepreparatory to another feed or advance stroke.

The sprocket 30, which is carried by the crank arm 28 at the outer endthereof, is revolved by the crank arm 28 with extreme positions shown inFIGS. 3 and 4, the

position of the crank arm 28 shown in FIG. 3 corresponding closely tothe extreme retracted position of the conveyor bed and that shown inFIG. 4 corresponding to the extreme forward or advanced position of theconveyor bed 10. The sprocket 30 meshes with a chain 40 fixed at itsrighthand end, as viewed in FIGS. 3 and 4, to the conveyor bed 10 andtraveling over an idler sprocket 42 rotatable on pin 44 mounted on afixed axis. The chain travels from the sprocket 42 under the sprocket3t) and is .fixed at its lefthand end to a pin 46 mounted in a fixedposition relative to the base of the conveyor. A spring 48 (FIG. 1)urges the conveyor bed 10 toward the right in the direction of advanceof the material 32, and the movement of the conveyor bed 10 iscontrolled by the deflection of the chain 40. That is, the spring 48keeps the conveyor bed 10 always at the farthest righthand position aspermitted by the slack or deflection of the chain caused by thesprockets 30 and 42. Preferably the idler sprocket 42 is spaced to theright of the shaft, 24 a distance substantially greaterthan the spacingof the pin 46 to the left-of the shaft 24, this lateral spacing ofsprocket 42 from the shaft 24 preferably being over twice that betweenthe pin 46 and the shaft 24.

As the crank arm 28 moves the sprocket 30 through the uppermost positionof the sprocket 30, the chain 40 straightens out completely and theconveyor bed. 10 is at the extreme righthand position thereof, and stopsmaterial advancing movement of the conveyor bed and the material isthrown. As illustrated in the diagram of FIG. 5, the conveyor drive 16gives a slow start to the feed stroke of the conveyor bed 10 so thatstatic frictional engagement is maintained between the conveyor bed 10and the material 32 being fed theerby, and the speed of the conveyor bed10 is then accelerated to a high speed, which changes abruptly tosubstantially no feed at the extreme end of the feed stroke to give thematerial a toss or throw. This breaks loose the static frictionalengagement between the material and the conveyor bed and causes thematerial to advance on farther in the feed direction. Then the drive 16moves the conveyor bed 10 in its retraction or return stroke and comesback to its original starting position of the feed stroke, after whichthe cycle'is repeated.

To make more abrupt the stopping of the conveyor bed 10 at the end ofits feed stroke, the path of the planetary sprocket may be such that itlifts slightly from full contact with the chain 40 when the chain 40 isfully straightened so that, during the ensuing, small portion of therevolution of the sprocket 30, the sprocket 30 is not bearing downwardlyagainst the chain 40 although the teeth of the sprocket are maintainedin mesh with the chain 40. This has'the effect of making the stop of thefeeding movement of the conveyor bed 10 more abrupt and also causes thestart of the retracting movement of the conveyor bed 10 to be moreabrupt. Since the sprocket 30 is rotated from its movement along thechain, it may be mounted eccentrically for rotation on the end of thecrank member 28, so that the throwing movement of the conveyor bed 10and the fast return of the conveyor bed 10 are increased.

In a reciprocating conveyor forming an alternate embodiment of theinvention shown in FIG. 6, a conveyor bed 60 is urged continuously tothe right by tension spring 62 to the extreme permitted by a chain orstrand 64 fixed at its righthand end to the conveyor bed 60 andtraveling over a guide sprocket 66 on a fixed axis and under a planetarysprocket 68 carried by a crank arm 70 revolved on the center of shaft72. The lefthand end of the chain 64 is secured to a fixed pin 75. Theshaft 72 is driven by an eccentric or elliptical gear 74 which is drivenby an elliptical gear 76 driven by shaft 78. The elliptical gear 76drives the elliptical gear 74 in a movement rapidly during one-half therotation of the gear 74 and more slowly during the other half, and thegear 74 is coupled to the crank arm 70 so that the rapid movement of thegear 74 occurs during the end of the forward feed of the conveyor bed 60so that the throw or tossing action of the conveyor drive is maximized.

A reciprocating conveyor shown in FIGS. 7 to 9 forming an alternateembodiment of the invention includes a reciprocating conveyor bed ortrough mounted by links 112 for horizontal reciprocation. The links 112are pivotally secured to the conveyor bed 110 at the upper ends thereof,and the lower ends thereof are mounted on fixed pivots 114, and themovement of the conveyor bed is between vertical parallel positions ofthe links 112 and positions of the upper ends of the links 112 to therighthand side only of the vertical positions thereof. The conveyor bedis reciprocated by a drive 116 which includes an electric motor 118driving a belt 120 to drive a flywheel 122. The flywheel 122 is keyed toa shaft 124 mounted in bearings 125 carried by vertical support plates126 and rotates crank disc 128 also keyed to the shaft 124. The plates126 are spaced .apart by spacers 134 and are supported by a base 136.The crank disk 128 revolves pin 130 about the center of the shaft 124.The drive 116 reciprocates the conveyor bed to feed material 132 with athrowing or tossing action toward the left, as viewed in FIG. 7, andstops the conveyor bed 110 sharply at the end of the feeding stroke ofthe conveyor bed to break static frictional engagement between thematerial and the conveyor bed, and then retracts the conveyor bedthrough a retraction stroke preparatory to another feed or advancestroke.

The crank disc 128 is keyed to the shaft 124 and carries the pin 130near the outer periphery thereof. The pin 130 is connected pivotally toan elongated connecting rod or link 140, and a pivotal joint 142connects the other end of the link to a pivotal arm 144 and a link 146pivotally connected by a pin 148 to a clevis 150 fixed to the conveyorbed 110. The arm 144 is freely pivotal on a pin 152 mounted on a fixedaxis.

The diagram of FIG. 10 shows the distance of movement of the conveyorbed relative to a fixed point. Operation of the crank member 128 causesthe conveyor bed 10 to be first moved in its feeding stroke from zero toabout 135, and then retracts the conveyor in the rest of the cycle ofrotation. The feed stroke starts the conveyor bed slowly and acceleratesthroughout the feed to high speed at the latter portion of the feedstroke, then stops the feed stroke abruptly and retracts the conveyorthroughout the remainder of the revolution. The high velocity of thefeed stroke during the latter part thereof, together with the abruptstop, gives a tossing or throwing action to the material, which breaksloose the static frictional engagement between the material and theconveyor bed, and throws the material on forward in the direction ofadvancement. This tossing or throwing action is accentuated by theaction of the links 112, which are raising the conveyor bed 110 duringthe feed stroke to increase the static frictional engagement between theconveyor bed and the material, which raising action is lessened at theend of the feed stroke. During the return stroke the links 112 move theconveyor bed down away from the material being advanced -to lessen thefrictional force therebetween. The combined action of the links 112 andthe asymmetrical crank drive has the effect of throwing the material andthen dropping the conveyor bed away from the material so that, duringthe return stroke, there is a minimum amount of friction between thematerial and the conveyor bed. The frequency of rotation of the.

crank member 28 is sufficiently low that excessive vibrations areavoided, and the conveyor has a very high feed capacity with low powerinput and with low maintenance required therefor.

In a spiral, elevating, reciprocating conveyor shown in FIGS. 11 to 14and forming an alternate embodiment of the invention, a spiral conveyorbed 210, which is generally similar to that disclosed and claimed in ourcopending application Serial No. 273,672, filed April 17, 1963, nowabandoned, is mounted on a cylinder 211 which carries'bearings 213slidable on a vertical post 214. A drive 216 generally similar to thedrive 116 oscillates the conveyor bed about the vertical arbor to advance material 232 up the conveyor bed. The drive 216 includes a base217 on which is mounted an electric motor 218 driving a flywheel 222through belt 220 The flywheel is keyed to shaft 224 mounted in alignedbearings 225 carried by the base 217 and a plate 223 carried by posts221. The flywheel carries crank pin 228. The posts 221 also supportupper plate 229. The crank pin 228 preferably is revolved by flywheel222 counterclockwise as viewed in FIG. 12. A link or connecting rod 240connects the pin 228 to a pin 242, which conmeets the link 240 to arm244 and link 246. The arm 244 is pivoted on one of the posts 221 byhearing 252,

and the link 246 is pivotally connected to pin 249 by a self-centeringbearing 251. The pin 249 is selectively fixed in one of holes 250 in arm25S fixed to the cylinder 211, A spring 258 urges the arm 255 clockwise,as viewed in FIG. 13. The link 246 is connected by the self-centeringbearing 251 for limited universal movement relative to the pin, and aself-centering bearing 159 connects the link 246 to the pin 242. The pin242 is rigidly carried by the arm 244.

The cylinder 211 with the spiral conveyor bed is suspended from threelinks 270 (FIGS. 11 and 14) which in the disclosed embodiment areflexible cables but can be two connecting rod portions connected byradial and thrust hearings to each other for rotation about thelongitudinal axes thereof. Self-aligning bearings 272 connect the cables270 to a ring 274 supported by annular plate 276 in any selected, fixedposition relative to the plate 276. The lower ends of the cables areconnected to the cylinder 211 by self-aligning bearings 278 and pins 280fixed to the cylinder 211. A pin 282 is adapted to key the ring 274 tothe plate 276 by projecting into bore 284 in the plate 276 and one ofnotches 286 spaced around the periphery of the ring 274. The plate 276is held in a fixed position by posts 288 fixed thereto and to the plate229.

To feed the material up the bed 210, the ring 274 preferably is set in aposition relative to the plate 276 such that, at the end of theretraction stroke and start of the feed stroke, the links 270 arevertical. Then, as the feed stroke takes place, the cylinder 211 turnsrelative to the ring and the lower ends of the links 270 swing upwardlyas illustrated in broken lines in FIG. 14. This raises the cylinder 211and conveyor bed 212 to lift the material thereon and also to press theconveyor bed more strongly against the material to increase the frictiontherebetween and thereby increase the feeding force. This pressingaction increases progressively as the feed stroke continues due toacceleration of the lifting action from the pendulum suspension of theconveyor bed 212. On the retraction stroke, the links 270 swing backdown to their vertical positions to drop out from under the materialbeing fed. To feed the material up the spiral conveyor bed 212, thecrank pin 228 is revolved in a counterclockwise direction as viewed inFIG. 12. This gives a fast return stroke and a feed-stroke as fast aspossible and still hold static frictional engagement between theconveyor bed and the material. The return stroke starts very fast andthe bed 212 also drops rapidly out of contact with the material to breakfree of the material. The trough or bed 212 can be provided with shallowsteps (not show) pressed therein to enhance the feeding action, andpreferably has between a 4% and a 6% grade or incline.

To feed material down the conveyor bed 212, the ring 274 is set so thatthe links 270 are vertical at the start of the clockwise movement of thearm 255, as viewed in FIG. 13. Then, during this clockwise feed stroke,the bed 212 is lifted by the links swinging clockwise as viewed in FIG.14 from their vertical positions. Then, in the return stroke, the bed212 is rapidly dropped out from the material.

The spring 258 (FIG. 13) acts as a dynamic energy storage device to aidthedrive in its rapid retraction of the conveyor bed in a clockwisedirection, the spring being stretched by the relatively slower feedstroke in the opposite direction. This smooths out the load on thedrive.

The above-described conveyors rapidly feed the material and with a lowspeed drive as compared with the speed of vibratory conveyors. Theconveyors are simple, rugged and highly eflicient. While the linearlyreciprocable conveyor beds of FIGS. 1 to 10 are disclosed as supportedby compression links, theconveyor beds obviously may be suspended byupper links in a manner similar to the suspension of the cylinder 211and spiral conveyor bed 212. p g

It is to be understood that the above-described arrangements are simplyillustrative of the application of the principles of the invention.Numerous other arrangeintents may be readily devised by those skilled inthe art which will embody the principles of the invention and fallwithin the spirit and scope thereof.

What is claimed is: 4

1. In a reciprocating conveyor,

a conveyor bed,

means mounting the conveyor bed for reciprocating movement along asubstantially horizontal path,

a chain,

means connecting one end of the chain to the conveyor bed,

means holding the other end of the chain,

guide means positioned between the ends of the chain against which thechain continuously bears,

a crank mounted rotatably on an axis positioned substantially nearer tothe holding means than to the guide means,

means revolved by the crank for engaging a portion of the chain at oneside of the guide means and sub-' stantially nearer to the holding meansthan to the guide means for deflecting the chain as the crank means isrotated to shorten and lengthen the overall length of the chain,

and means for urging the conveyor in the direction such as to tensionthe chain.

2. In a reciprocating conveyor,

a conveyor bed mounted for reciprocating movement,

a crank arm rotatable on a predetermined axis,

means for rotating the crank arm,

a deflecting sprocket revolved by the crank arm,

a chain engaged by the deflecting sprocket,

means holding one end of the chain,

means securing the other end of the chain to the conveyor bed,

an idler sprocket positioned between the deflecting sprocket and the endof the chain fixed to the conveyor bed for holding the chain against thedeflectmg sprocket,

the holding means being spaced substantially closer than the idlersprocket to said axis,

and spring means for urging the conveyor bed in a direction such as tomaintain the chain in a taut condition.

3, In a reciprocating conveyor,

a conveyor be'd mounted for reciprocating movement,

a chain,

means holding one end of the chain at a predetermined point spaced apredetermined distance from the axis of rotation of the crank arm,

means securing the other end of the chain to the conveyor bed,

spring means for urging the conveyor bed in the direction such as tomaintain the chain in a taut condition,

a crank arm,

means for rotating the crank arm on a predetermined axis,

a deflecting sprocket revolved by the crank arm along a circular path inengagement with the chain,

and an idler sprocket positioned between the deflecting sprocket and theend of the chain fixed to the conveyor bed,

the idler sprocket being spaced substantially farther than from saidaxis than said predetermined distance.

4. In a reciprocating conveyor,

a conveyor bed,

means mounting the conveyor bed for reciprocating movement along asubstantially horizontal path,

strand means,

means connecting one end of the strand means to the conveyor bed,

means holding the other end of the strand means at a fixed point,

guide means positioned between the ends of the strand means againstwhich the strand means continuously bears,

I D a crank mounted r-otatably on an axis positioned substantiallynearer to said fixed point than to the guide means,

means revolved by the crank for engaging the portions of the strandbetween the guide means and the fixed point and substantially nearer tosaid fixed point than to the guide means for deflecting the strand meansbetween said points as the crank is rotated to shorten and lengthen theoverall length of the strand means,

and means for urging the conveyor in a direction such as to tension thestrand means.

References Cited by the Examiner UNITED STATES PATENTS 1,411,855 4/1922Loeb 7454 1,596,465 8/ 1926 Stebbins.

1,627,673 5/ 1927 Stebbins.

1,763,307 6/1930 Hoflmann.

2,818,968 1/1958 Carrier.

2,926,773 3/ 1960 Alvord.

HUGO O. SCHULZ, Primary Examiner".

EDWARD A. SROKA, Examiner.

1. IN A RECIPROCATING CONVEYOR, A CONVEYOR BED, MEANS MOUNTING THECONVEYOR BED FOR RECIPROCATING MOVEMENT ALONG A SUBSTANTIALLY HORIZONTALPATH, A CHAIN, MEANS CONNECTING ONE END OF THE CHAIN TO THE CONVEYORBED, MEANS HOLDING THE OTHER END OF THE CHAIN, GUIDE MEANS POSITIONEDBETWEEN THE ENDS OF THE CHAIN AGAINST WHICH THE CHAIN CONTINUOUSLYBEARS, A CRANK MOUNTED ROTATABLY ON AN AXIS POSITIONED SUBSTANTIALLYNEARER TO THE HOLDING MEANS THAN TO THE GUIDE MEANS, MEANS REVOLVED BYTHE CRANK FOR ENGAGING A PORTION OF THE CHAIN AT ONE SIDE OF THE GUIDEMEANS AND SUBSTANTIALLY NEARER TO THE HOLDING MEANS THAN TO THE GUIDEMEANS FOR DEFLECTING THE CHAIN AS THE CRANK MEANS IS ROTATED TO SHORTENAND LENGTHEN THE OVERALL LENGTH OF THE CHAIN, AND MEANS FOR URGING THECONVEYOR IN THE DIRECTION SUCH AT TO TENSION THE CHAIN.